1 /*
2 * Copyright (C) 2005 IBM Corporation
3 *
4 * Authors:
5 * Seiji Munetoh <munetoh@jp.ibm.com>
6 * Stefan Berger <stefanb@us.ibm.com>
7 * Reiner Sailer <sailer@watson.ibm.com>
8 * Kylene Hall <kjhall@us.ibm.com>
9 *
10 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
11 *
12 * Access to the eventlog extended by the TCG BIOS of PC platform
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
18 *
19 */
20
21 #include <linux/seq_file.h>
22 #include <linux/fs.h>
23 #include <linux/security.h>
24 #include <linux/module.h>
25 #include <linux/slab.h>
26 #include <acpi/acpi.h>
27
28 #include "tpm.h"
29 #include "tpm_eventlog.h"
30
31 struct acpi_tcpa {
32 struct acpi_table_header hdr;
33 u16 platform_class;
34 union {
35 struct client_hdr {
36 u32 log_max_len __packed;
37 u64 log_start_addr __packed;
38 } client;
39 struct server_hdr {
40 u16 reserved;
41 u64 log_max_len __packed;
42 u64 log_start_addr __packed;
43 } server;
44 };
45 };
46
47 /* read binary bios log */
read_log(struct tpm_bios_log * log)48 int read_log(struct tpm_bios_log *log)
49 {
50 struct acpi_tcpa *buff;
51 acpi_status status;
52 void __iomem *virt;
53 u64 len, start;
54
55 if (log->bios_event_log != NULL) {
56 printk(KERN_ERR
57 "%s: ERROR - Eventlog already initialized\n",
58 __func__);
59 return -EFAULT;
60 }
61
62 /* Find TCPA entry in RSDT (ACPI_LOGICAL_ADDRESSING) */
63 status = acpi_get_table(ACPI_SIG_TCPA, 1,
64 (struct acpi_table_header **)&buff);
65
66 if (ACPI_FAILURE(status)) {
67 printk(KERN_ERR "%s: ERROR - Could not get TCPA table\n",
68 __func__);
69 return -EIO;
70 }
71
72 switch(buff->platform_class) {
73 case BIOS_SERVER:
74 len = buff->server.log_max_len;
75 start = buff->server.log_start_addr;
76 break;
77 case BIOS_CLIENT:
78 default:
79 len = buff->client.log_max_len;
80 start = buff->client.log_start_addr;
81 break;
82 }
83 if (!len) {
84 printk(KERN_ERR "%s: ERROR - TCPA log area empty\n", __func__);
85 return -EIO;
86 }
87
88 /* malloc EventLog space */
89 log->bios_event_log = kmalloc(len, GFP_KERNEL);
90 if (!log->bios_event_log) {
91 printk("%s: ERROR - Not enough Memory for BIOS measurements\n",
92 __func__);
93 return -ENOMEM;
94 }
95
96 log->bios_event_log_end = log->bios_event_log + len;
97
98 virt = acpi_os_map_memory(start, len);
99 if (!virt) {
100 kfree(log->bios_event_log);
101 printk("%s: ERROR - Unable to map memory\n", __func__);
102 return -EIO;
103 }
104
105 memcpy_fromio(log->bios_event_log, virt, len);
106
107 acpi_os_unmap_memory(virt, len);
108 return 0;
109 }
110